A warning label is being slapped on articles that clearly have no basis in fact or reality — at least some of them.

The giant social network first promised to roll out a "disputed" tag in December. Over the weekend, it made its debut in the U.S. Facebook declined to comment.

Among the disputed offenders that people spotted on Facebook: A fictionalized story, "Trump's Android Device Believed To Be Source of Recent White House Leaks," from a fictional publication, "The Seattle Tribune." The story carried a disputed label with links to fact-checking services that explained why it was not true.

The website has a disclaimer that it is a "news and entertainment satire web publication." But the story fooled people anyway.

The "disputed" tag is part of Facebook's grand plan to crack down on fake news as the company tries to tamp down the controversy over its role in the spread of misinformation that sharpened political divisions and inflamed discourse during and after the presidential election.

"They're gonna run out of flags," joked one Facebook user.

"Guarantee the people who share fake news all the time will use this to say they are being censored, or that Facebook is forcing liberal bias down their throats, or whatever," commented another. "I expect it to strengthen their resolve not make them see their bias for what it is."

Facebook has been reluctant to put itself in the position of judging what content is misleading, resisting calls that it has become a de facto news publisher, exercising editorial judgment with the power to sway the minds of billions.

BuzzFeed News found that people who say they rely on Facebook as a major source of news were more likely to believe politically slanted fake news stories. An earlier BuzzFeed News analysis found that top-performing fake news articles on the election generated more engagement on Facebook than articles from major news outlets in the last months of the presidential campaign.

Fake news creates significant public confusion about current events with nearly one-fourth of Americans saying they have shared a fake news story, according to a Pew Research Center survey.

To flag a fake news article, users click on the upper right hand corner of a post. Facebook says its algorithms are also rooting out fake articles.

News articles flagged by users will be sent to third-party fact-checking organizations that are part of Poynter's International Fact Checking Network, Facebook says. If the article is identified as fake by the fact-checking organizations, it will get flagged as "disputed" and there will be a link to an article explaining why. Stories that have been disputed will also get pushed down in News Feed.

Facebook users who try to share a disputed article are asked if they are sure they want to share it.